A cock mungler is a real jackass.
To mungle someones cock is to do something that just destroys them, like in a game.
To get your cock mungled would be to get destroyed, like in a game.
You may have to use various objects to mungle somones cock.
Like a gold fish, a packet of crayons a bucket of vasiline and a zippo lighter.
A true cock mungler can mungle someones cock with his barehands.

Dude I think that guy just mungled my cock!
Wow that guy is a total cock mungler.
Man I just mungled that guys cock.